Microstructure and tensile properties of intercritically quenched 0.3C-Cr-Mn-Si steel

Abstract

Spheroidized and prequenched 0.3C-Cr-Mn-Si steel was quenched from the intercritical α+γ temperature range and tempered at 250°C. It was shown that intercritical quenching can appreciably improve the ductility of the steel, for the same strength level, compared to conventional quenching and tempering. Additionally, prequenching from the γ region before intercritical quenching gives even larger improvements in the ductility of the steel than merely intercritical quenching, as a result of the development of a lamellar martensitic-ferritic dual-phase structure. The tensile behaviour of the intercritically quenched steel is discussed with emphasis on the strain-hardening exponents of various dual-phase structures.

MST/93